Looper mechanism for sewing machines



c. c. SMITH LOOPER MECHANISM FOR SEWING MACHINES April 19, 1932.

Filed Dec. 28, 1929 April 19, 1932. c. c. SMITH LOOPER MECHANISM FORSEWING MACHINES Filed Dec. 28, 1929 2 Sheets-Sheet 2 -lll Patented Apr.19, 1932 CLARENCE C. SMITH, OIE' CHICAGO, ILLINOIS, ASSIGNOR TO UNIONSPECIAL MACHINE I COMPANY, F CHICAGO, ILLINOIS, A CORPORATION 0FILLINOIS LOOPER MECHANISM FOR SEWING MACHINES l Application filedDecember 28, 1929. Serial No. 417,170.

The invention relates to new and useful improvements in a loopermechanism for sewing machines, and more particularly to the mechanismfor imparting oscillations to the looper.

An object of the invention is to provide a looper operating mechanismwherein the eccentric member which imparts oscillations to the looper issecured to the actuating shaft therefor by a sleeve which is rigidlyheld in a set position on said shaft. Y

A further object of the invention is to provide a machine of the abovecharacter wherein the sleeve which supports the eccentric also serves tojoin the sections of the actuating shaft which operate the feed and theneedle lever respectively.

In the drawings Figure 1 is a plan view of the parts beneath a portionof the cloth plate showing the looper mechanism and the means forimparting oscillating` motions to the looper..

F ig. 2 is a View partly in front elevation and partly in section of thelooper operating mechanism.

f ig. 3 is an enlarged sectional View on Jthe line 3 3 of F ig. 1.

Fig. 4 is a detached perspective View showing the sleeve for joining theends of the shaft sections and also the eccentric formed integraltherewith which impart-s oscillations to the looper.

The invention is directed to a looper operating mechanism for sewingmachines and is shown as applied to a sewing machine having a supportingbed 1 carrying a cloth plate 2. Mounted for rotation in suitablebearings in the cloth plate is the main shaft which consists of twosections 3 and v4. The section 3 is the driven section and carries theusual crank or eccentric member for imparting vibrations to the needlelever. The section 4 operates the feed and imparts lateral or needleavoiding movements to the looper. The ends of the shaft sections 3 and 4are joined Located in the keyways in the shaft sections and in thesleeve is a square key 6.7) which positively -gcins the shafts. Mountedon the coupling sleeve 5 and formed as an integral part thereof is aball eccentric 8. The keyway 5a in the sleeve extends all the waythrough the connecting member supporting the eccentric and through theeccentric. Cooperating with this ball eccentric 8 is an ec` centricstrap 9. The eccentric strap 9 engages a ball stud 10 carried by an arm11 of a rock lever 12.V This rock lever 12 is mounted on a suitablesupporting shaft carried by the bed of the machine. The rock lever alsoincludes an arm 13 carrying a ball stud 14.

There are two loopers shown in the drawings which are indicated at 15and 16. These two loopers are mounted on a. looper rocker 17 and areconnected by a link 1.8. A link 19 is attached to the looper 15 and tothe ball stud 14. This link 19 is made in sections and is adapted to bebuckled in order to position the loopers for threading. This link whichis capable of buckling forms no part of the present invention, but isshown, described and claimed in the application of Frederick F. Zeierand Clarence C. Smith` filed August 27, 192e, serial No. 302,229.

The looper rocker 17 is cscillated by means of an eccentric 2O mountedon the shaft section 4. An eccentric strap 21 cooperating with theeccentric engages a ball stud 22 carried by an arm 23 which is rigidlyattached to the shaft 24 on which the looper rocker 17 is clamped.

The feed bar carrying the feed dog is indicated at 25 in the drawings.This feed bar is connected to a feed rocker 26. The feed rocker isoscillated by a link 27 cooperating with a crank on the end of theshaftsection 4.

From the above it will be apparent that the eccentric 8 is connected tothe shaft sections 3 and l through the connection of the coupling sleeveto these shaft sections. The shaft section 3 passes through theeccentric. The coupling sleeve serves as the sole means for supportingthe eccentric and forms a very rigid support therefor insuring itsproper seating on the shaft sect-ions 3 and 4. By making the shaft insections and coupling the same by the sleeve, it will be readily notedthat the section 3 may be provided with a crank and suitably inserted inthe bearings therefor, while the section el is also provided i ith a.crank and inserted in its supporting bearings. by an endwise motion.After the two shafts are in place they are joined by this couplingsleeve and the square key lying in the keyways will always secure thetwo shaft sections in a predetermined timed relation to each other. Theywill likewise secure the eccentric to the joined shaft sections in apredetermined time relation thereto. Through tlhis keyw'ay lne crank atthe feed end of the main shaft and the crank at the needle operating endof the main shaft and also the eccentric for moving the looper into andout of the needle thread loops are all positiv-ely joined in apredetermined timed rela-tion to each other. T he assembling of theparts cannot disturb this timed relation.

It is obvious that minor changes in the details of construction and thearrangement of the parts may be made without departing from the spiritof the invention as set forth in the appended claims.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent, is:

l. A looper mechanism for sewing machines comprising a sectional mainactuating shaft, a coupling sleeve for joiningthe ends of said sectionalshaft, means for securing said sleeve to the ends of said shaft sectionsfor joining the same, an eccentric formed integral with said sleeve, andactuating devices operated by said eccentric for moving the looper intoand out of the needle thread loops.

2. A looper mechanism for sewing machines comprising a sectional mainactuating shaft, a coupling sleeve for joining the ends of saidsectional shaft, means associated with said coupling sleeve and the endsof said shaft sections for securing said sections together in a.predetermined timed relation, an eccentric formed integral with saidsleeve, and actuating devices operated by said eccentric for moving thelooper into and out of the needle loops.

3. In a sewing machine, a sectional main actuating shaft, one of saidsections carrying CLARENCE C. SMITH.

